1. Evolution
The process of natural selection is happening in species today. Natural Selection can be studied directly. Demonstrated in lab and nature over a wide variety of species.
We cannot study the evolutionary history of life on earth directly. Because it happened in the past!
Study PATTERNS in biological data we observe today and determine the historical process that left the patterns we observe given what we know about how natural selection works.
Evidence for life’s evolutionary history, comes from several fields of study. These include: Fossil record, anatomy, developmental biology, biochemistry, and genetics

2. Charles R. Darwin

3. “tongue stones”
1600’s Nicholas Steno

4. Fossils

5. Geologic layers bottom = old top = new
What is a fossil? Remains of species that lived in the past. Hard tissues (such as bone and shells) mineralized underground by geological processes over time.
There are distinct layers in the earth’s crust. You can see these layers in road cuts or just on hill sides here in the desert. The oldest rocks are found on the bottom layers. Progressively younger rocks are found on top of each other. So are fossils randomly distributed among the aged layers? NO.
The basic pattern revealed is so: in the older layers we find organisms that are more primitive and least resemble any modern forms. In younger layers you see a pattern of fossils that represent organisms that more closely resemble modern forms. Until, finally, on the upper most layers, you find the remains of organisms that most closely resemble modern forms.

6. The Voyage of the Beagle (1831-1836)
Charles Darwin

7. CHARELS DARWIN
ALFRED R. WALLACE

8. Hyracotherium vasacciensis 55 million years old
Meet the oldest recognizable member of the horse family, an animal about the size of a miniature poodle. It brought in a major evolutionary trend for horses--the move from browsing to grazing as a way of life. Its descendants developed tougher teeth to grind grass and longer limbs to flee predators across the plains.

9. Built for speed! 1 million years ago to the present 13 mya 25 mya
The fossil record provides evidence that traces 55 million years of evolution in the horse.
The central digit of horses became increasingly stronger while the "side toes" became less important and are virtually lost in the modern horse.
36 mya
55 mya

10. Transitional forms

11. Transitional forms

12. Homology GRASPING RUNNING SWIMMING FLYING
Anatomy: structural evidence comes from the study of anatomy
The pattern we observe in closely related organisms is variations on a theme of similar anatomy. For example, mammals exhibit a wide variety of functions in their limbs. Even though the functions vary, the structure is remarkably similar.
Natural selection can only work on the available information that’s in the genes. It can only play with the cards the genome deals, it can’t pull an Ace from its sleeve. In this case of mammal limbs, the cards dealt are the humerus, the ulna, the radius, the carpal bones, the meta-carpal bones, and the phalanges. Natural selection has acted on various aspects of the available genetic information and the resulting pattern is shown in a suite of modified descendants from a common ancestor which had the same set of bones.
Homology

13. Homology Anatomy: structural evidence comes from the study of anatomy
The pattern we observe in closely related organisms is variations on a theme of similar anatomy. For example, mammals exhibit a wide variety of functions in their limbs. Even though the functions vary, the structure is remarkably similar.
Natural selection can only work on the available information that’s in the genes. It can only play with the cards the genome deals, it can’t pull an Ace from its sleeve. In this case of mammal limbs, the cards dealt are the humerus, the ulna, the radius, the carpal bones, the meta-carpal bones, and the phalanges. Natural selection has acted on various aspects of the available genetic information and the resulting pattern is shown in a suite of modified descendants from a common ancestor which had the same set of bones.
Homology

14. Development fish chicken pig human Developmental Biology:
Closely related organisms share similar developmental pathways
In the early embryonic stages in vertebrates, they all have very similar structure. For example, they all have in the early stages, gill slits and tails. The process for this pattern can be explained because the genetic information that guides their development is nearly the same. This implies these vertebrates evolved from a common ancestor.
pig
human
Development

15. Vestigial Structures salamander baleen whale boa constrictor
Even after an animal has completed its embryonic development, there are some features in adults that provide evidence of evolution from a previous ancestor. This evidence comes in the form of vestigial structures: an inherited anatomical structure in an organism that no longer functions in the way it did in the ancestor.
The salamander is an example of an animal that has a pelvis and legs used for walking. Wales do not have hind legs for walking. However, they have a vestigial pelvis that is retained from an ancestor that most likely used it for walking. Likewise, some species of snake have a vestigial pelvis and leg bones (here are the vestigial pelvis and leg bones from an Anaconda)
Vampire Bats have molars, but they (as you know) persist on a solely liquid diet.

16. At the most fundamental biochemical levels, all living cells are very similar
DNA
Genetic code
20 Amino Acids
Energy molecule, ATP
At the most fundamental biochemical levels, all living cells are very similar.
Pattern: What do they all share? (list) DNA, genetic code, 20 amino acids, energy molecule ATP

17. 600 million years ago (mya) 500 mya 440 mya 400 mya 350 mya 270 mya
In several of the above examples I just gave, closely related organisms share X. If I define closely related as sharing X, this is an empty statement. It does however, provide a prediction. If two organisms share a similar anatomy, one would then predict that their gene sequences would be more similar than a morphologically distinct organism. This has been spectacularly borne out by the recent flood of gene sequences -- the correspondence to trees drawn by morphological data is very high. This diagram shows the genetic relationship among these major groups of animals based on how similar their DNA is. For example, mammals as a group all share more similar DNA than birds. The shark and the carp have more similar DNA than do the rest of the vertebrates and so on.
135 mya
70 mya
present

18. Variation Inheritance Selection Time
In several of the above examples I just gave, closely related organisms share X. If I define closely related as sharing X, this is an empty statement. It does however, provide a prediction. If two organisms share a similar anatomy, one would then predict that their gene sequences would be more similar than a morphologically distinct organism. This has been spectacularly borne out by the recent flood of gene sequences -- the correspondence to trees drawn by morphological data is very high. This diagram shows the genetic relationship among these major groups of animals based on how similar their DNA is. For example, mammals as a group all share more similar DNA than birds. The shark and the carp have more similar DNA than do the rest of the vertebrates and so on.